In a typically integrated circuit formation process, semiconductor wafers, each including a plurality of identical semiconductor chips, are manufactured first. After the manufacturing, the semiconductor wafers are sawed to separate the semiconductor chips, so that each of the semiconductor chips may be packaged individually.
On a semiconductor wafer, scribe lines are placed between the semiconductor chips. The scribe lines may be free from integrated circuits, or have test circuits formed therein, wherein the test circuits may be sacrificed without affecting the functionality of the semiconductor chips.
Typically, seal rings are formed to protect the integrated circuits in the semiconductor chips from moisture and contaminations. However, for the packaging processes, some of the back-end-of-line processes need to be performed for forming bond pads and/or mounting solder balls. These processes include forming protection layers (molding compounds), forming redistribution lines, and forming bond pads. Various layers of materials and corresponding interfaces are thus created. These interfaces are not properly protected, and some of the interfaces may be exposed to the external environment after the die-sawing process for separating the semiconductor chips. As a result, moisture may penetrate through these interfaces and corrodes the copper lines in the semiconductor chips. In addition, since the formation of copper lines often involves fluorine, the corrosion of the copper lines further results in the fluorine to be released. Fluorine has the effect of accelerating the corrosion of the aluminum pad by moisture. Further, the exposure of the interfaces may further cause the delamination of the protection layers. Any of the above-discussed problems may cause the degradation of the circuit performance, or circuit failure. A new integrated method for protecting the interfaces from moisture penetration is thus needed.